POLISHING COMPOSITION

The present invention provides a polishing means which is capable of improving the flatness of a substrate without significantly reducing the polishing rate. The present invention specifically provides a polishing composition which contains inorganic particles, water and a modified polyalkylene oxide that is represented by formula (1). (In the formula, each R1 independently represents a group represented by R11-(O-R12)x-; each R11 independently represents an alkyl group having 1-24 carbon atoms; each R12 independently represents an alkylene group having 2-4 carbon atoms; x represents an integer of 0-500; each R2 independently represents a hydrocarbon group; each R3 independently represents an alkylene group having 2-4 carbon atoms; n represents an integer of 1-1,000; and m represents an integer of 1 or more.). 本发明提供即使不显著降低研磨速率也能够改善基板的平坦性的研磨方法。更具体而言，本发明提供一种研磨用组合物，其含有无机粒子、水和式(1)所表示的聚环氧烷改性物。(式中，R1各自独立地表示R11-(O-R12)x-所表示的基团。R11各自独立地表示碳原子数1～24的烷基，R12各自独立地表示碳原子数2～4的亚烷基，x表示0～500的整数。R2各自独立地表示烃基。R3各自独立地表示碳原子数2～4的亚烷基。n